Door-check.



No. 628,795. Patsntod July II, i899. C. B. HARKNESS.

0R CHECK.

(App 'ca ion led Kay 13, 1899.) (No Modal.)

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mamy, d* ld? 1 TINTTnn STaTns PATnNT CHARLES BRADLEY HARKNESS, OFBOSTON, MASSACHUSETTS.

, DOOR-CHCK.

SPECIFICATION forming part of Letters Patent No. 628,795, dated July 11,1899. Application ined May is, 1899. Senn No. 716,627. (No model.)

To all whom t may concern:

Be it known that I, CHARLES BRADLEY HARKNESS, of Boston, Suffolk county,Massachusetts, have invented a new and useful Improved Door-Check, ofwhich the following is a specification, reference being had to theaccompanying drawings, in which" Figure l is a central sectional sideelevation of my device. Fig. 2 is a front elevation. Fig. 3 is a plan ofFig. 2. Fig. 4 is a side elevation showing the contrivance in operation.

My invention is a movable doorfcheck designed to prevent a door fromswinging upon its hinges and to hold it fixed in any desired position.

I have shown in a former patent granted to me, No. 565,896, dated August18, 1896, a contrivance for attaining the same end, and my presentinvention is an improvement upon that 'contrivance by which certaindefects are remedied and certain additional advantages attained.

i In the drawings, A is a base.

B is a springsbox open at the top, which is secured to the base byscrews b and which has a slot b upon one side. The box B is mounted atone end of the base, and the slot faces the other end of the base. (SeeFigs. l and 3.) Within the box B another box D is placed, its upper end,which is closed, projecting through the open end of box B, and a bracketd, which is fast to the lower edge of box D, projects through the slot bin box B. Vithin the box B, its upper end resting within the box D, asshown, is a stout spring E, which tends constantlyto eject box D frombox B and which would succeed were it not for the bracket d, whichengages the top of slot b and prevents this. It will be obvious thatthese various parts are assembled in the relations I have describedbefore the box B is secured upon the base A.

Upon the bottom of the base A and upon the top of bracket d suitablestrips of soft rubber R are secured.

The mode of operation is as follows: The check is placed upon the floorat the place where it is desired to hold the door, the foot of theoperator is pressed upon the top of box D, the spring E is compressed,andthe bracket d forced down, if necessary, until it is in contact withthe base A. The bottom of the door is then swung over the bracket d andthe' foot of the operator is lifted, allowing the spring E to throw upbox D and all connected parts. The result is that the rubber R upon thebottom of base A is forced against the iioor and the rubber upon the topof bracket (l is forced against the bottom of the door, thus creating astrong frictional resistance to move; ment of the door in eitherdirection.

The advantages of this construction over that shown in my prior patentare obvious, the principal one being that the contrivance can be used tocheck any door the bottom of which swings above the -licor at a distanceequal to or greater than the combined thickness of the base A andbracket d. In my earlier contrivance the telescoping boxes,

`with the contained spring, were placed be neath the door, and as it isobvious that the spring and boxes would require considerably more depthas a minimum than the mere thickness of two plates like base AV andbracket CZ it is clear that the contrivance could not be placed beneathmany doorsviz., those which swung at all close to the iioor. The rangeof upward and downward movement in my present contrivance, in which thespring is operated at one side, is practically unlimited and is fullyequal in one instrument to any variation likely to be found betweendoors, so that'in my present contrivance one check can be used for anydoor in the house.

Another advantage of my present contrivance is its simplicity and thepossibility of a direct application of the power of the operator incompressing and releasing the spring.

In practice I find that' the base.A should project well beyond thecenter of the bearing-surface of bracket d, for otherwise the check willmanifest a tendency to tip. The drawings show the proportions which Ihave found successful.

It will be obvious that the bracket d, cooperating with the top of slotb, forms a stop to hold the two boxes in connection despite the effortof spring E, and this function is in- IOO b; spring E interposed betweenthe boxes B and D, all organized and operating as described.

CHARLES BRADLEY HARKNESS.

Vitnesses:

O. R. MITCHELL, JOSEPH T. BRENNAN.

